Lysine requirement for tambaqui juveniles

• Autor(a) principal: Silva, Janayra Cardoso
• Data de Publicação: 2018
• Outros Autores: Bomfim, Marcos Antonio Delmondes, Lanna, Eduardo Arruda Teixeira, Ribeiro, Felipe Barbosa, Siqueira, Jefferson Costa de, Sousa, Thalles José Rêgo de, Marchão, Rafael Silva, Nascimento, Daphinne Cardoso Nagib do
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Semina. Ciências Agrárias (Online)
• Texto Completo: https://ojs.uel.br/revistas/uel/index.php/semagrarias/article/view/31128
• topic: Body composition; Colossoma macropomum; Initial growth phase; Protein nutrition.; Colossoma macropomum; Composição corporal; Fase inicial; Nutrição proteica.

The aim of this study was to determine the requirement for lysine in the diet of juvenile tambaqui (Colossoma macropomum). In total, 750 juvenile fish (0.34 ± 0.02g) were distributed in tanks arranged in a randomized block design with six treatments, five replications in two blocks, and 25 fish per unit, for 50 d. Six levels of digestible lysine were tested (1.30, 1.48, 1.66, 1.84, 2.02, and 2.20%), in formulated diets based on the ideal protein concept. The performance, feed efficiency, daily deposition of protein and body fat, and nitrogen retention efficiency of the fish were evaluated. The consumption of rations and protein, specific growth rate, body composition, and deposition of body fat were not influenced by the lysine levels tested. The consumption of digestible lysine increased linearly and the efficiency of digestible lysine for weight gain decreased linearly with the increase in lysine levels. The levels of digestible lysine that optimized weight gain and body protein deposition were estimated at 1.73 and 1.78%, respectively. The feed conversion and nitrogen retention efficiency were most improved at 1.66% and 1.84%, respectively. The recommended level of dietary lysine for providing better weight gain and body protein deposition in juvenile tambaqui is 1.78%, equivalent to 2.00% total lysine.